I'm a jockey caught in situation and changing colours (11)
I believe the answer is:
iridescence
'changing colours' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'i'm a jockey caught in situation and' is the wordplay.
I cannot really see how this works, but
'i'm' could be 'i' (I've seen this in other clues) and 'i' is located in the answer.
'jockey' could be 'ride' (I've seen this in another clue) and 'ride' is located in the answer.
'caught' could be 'c' (cricket abbreviation) and 'c' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for iridescence that I've seen before include "Play of rainbow colours" , "Shimmering colour" , "Effect of shimmering rainbow colours" , "shimmering display" , "Shimmer of luminous colours" .)